1. Field of the Invention
The present invention relates to a graft assembly for repairing blood vessels, preferably vessels affected by lesions in the vessel wall, more preferably lesions of the type known as dissecting aneurysms, and particularly relates to a graft assembly, the use thereof and method for intraluminal implanting the graft assembly into a blood vessel affected by a lesion wherein no firm walls of the vessel are available to get a firm and stable implantation of a conventional graft. The invention is particularly suited for repairing thoracic dissecting aneurysms, although it is not limited thereto.
2. Description of the Prior Art
It is well known that blood vessels are affected by diseases generating deformations and damages in the vessel wall, particularly the aortic vessel which may be subject to aneurysm formation and severe atherosclerotic disease resulting in multiple sclerosis. In addition, the blood vessels may be affected by other types of damages like occlusions. In any of these afflictions it is common to carry out a repairing method in the compromised region of the vessel in order to preserve the health or even the life of the patient. Previously, such afflictions were repaired by traditional surgery in order to reach the affected vessel, making corresponding incisions in the patient""s body and through the vessel to implant, within the vessel, a graft or prosthesis in order to replace the portion of the vessel affected by the disease.
Nowadays, most of the above affections and lesions are treated by implanting one or more prosthesis, particularly endoluminal stent-grafts, into the affected artery or vein. The endoluminal stent-graft is typically comprised of a metallic stent, such as a mesh-type stent, the stent being of the self-expanding or balloon expandable type, and a liner or tubular graft material which is affixed, by sutures for example, to the inside or the outside of the metallic stent. The stent-graft in a collapsed condition is delivered to the affected portion of the vessel via a catheter and, once in the correct position, the stent-graft is deployed, either by means of a balloon or by letting the self expanding stent to resiliently expand upon moving out of the catheter, in order to cause the stent-graft to be firmly affixed against the vessel wall, inside the blood vessel.
Many endoluminal grafts are well known and widely used in the art. U.S. Pat. No. 4,922,905 relates to a catheter and discloses a tubular endoprosthesis device having a wall structure comprised of a tube-like, knitted open fabric of loosely interlocked loops of metallic filament material, said tube-like fabric being radially inwardly deformed relative to its as-knit form and is capable of progressive permanent deformation with attendant radial expansion by means of the catheter to attach the endoprosthesis inside a blood vessel to be repaired.
WO 83/03752 to Wallsten, Hans Ivar, discloses a prosthesis comprising a one-piece expandable tubular body to be inserted into a vascular vessel.
WO 90/15582 to Trout, Hugh, discloses an aortic graft comprising a substantially cylindrical graft material with attachment means which comprise a plurality of post and hook assemblies to provide firm attachment of the aortic graft against the aortic wall.
The above referred stent-grafts may be used satisfactorily provided that a healthy and firm wall of the vessel is available surrounding the lesion so that the stent-graft may be affixed to such firm wall in stable and fixed conditions. It is common to find lesions extending along a large portion or length of the affected vessel with a bifurcation, namely an inlet or outlet vessel branch, located in the affected portion, between the healthy portions of the wall, or close to the afflicted portion. Under these circumstances if a short stent-graft is implanted, the same has an insufficient length to extend along the entire afflicted portion and, while an end of the stent-graft may be located over the healthy portion of the vessel wall, for obtaining a proper retention, the opposite end will be in the lesion where no reliable retention is available. If a larger stent is implanted to have both ends of the graft implanted a healthy and firm wall parts, while covering the entire length of the afflicted portion, it will occlude any bifurcation, namely inlets or outlets of vessel branches located in the lesion-affected portion of the vessel.
It would be therefore desirable to develop a graft for use in repairing blood vessels with lesions wherein the wall of the vessel is not in conditions to receive and firmly retain an implanted graft in the desired and necessary location inside the vessel. It would also be desirable to have a graft to selectively repair the lesions in the vessel wall without occluding any outlet or inlet of a branch in or close to the lesion.
It is therefore an object of the present invention to provide a multi-component stent-graft assembly for repairing a lesion in a blood vessel, preferably a thoracic dissecting aneurysm, the assembly comprising a frame stent that is affixed to the vessel, in the healthy portions of the vessel and extending along the entire lesion of the vessel, and a stent-graft which is affixed against the inside of the frame stent, the stent graft being located at the desired locations within the affected portion of the vessel no matter the vessel wall is or not in conditions to retain the stent-graft, because the retention will be provided by the frame stent.
It is also an object of the present invention to provide a multi-component endoluminal graft assembly for repairing blood vessels affected by one or more lesions, the multi-component graft assembly comprising an outer frame stent for endoluminaly affixing to the blood vessel, and at least one hollow tubular stent-graft for being arranged coaxially within said outer frame stent and affixed to the outer frame stent.
It is still another object of the present invention to provide a multi-component endoluminal graft assembly for repairing blood vessels affected by one or more lesions, the multi-component graft assembly comprising an outer frame stent, either self-expanding or a balloon expandable stent, and at least one hollow tubular stent-graft comprising an inner stent, and a graft made of fabric or textile material and coaxially arranged over the inner stent, wherein the outer frame stent is to be endoluminaly affixed to the blood vessel and the stent-graft is to be arranged coaxially within said outer frame stent and affixed to the outer frame stent once the outer frame stent is expanded and affixed against the vessel, whereby the textile graft is to remain sandwiched between the outer frame stent and the inner stent.
It is even another object of the present invention to provide a use of the above multi-component endoluminal graft assembly, wherein the multi-component graft is endoluminaly implanted in a blood vessel affected by at least one lesion, wherein the outer frame stent is affixed to the vessel and the at least one stent-graft is coaxially arranged within the outer frame stent and affixed to the outer frame stent.
It is a further object of the present invention to provide a use of the above multi-component endoluminal graft assembly, wherein the multi-component graft is endolumlnaly implanted in a blood vessel affected by at least one lesion, wherein he outer frame stent is affixed to the vessel and the at least one stent-graft is coaxially arranged within the outer frame stent and affixed to the outer frame stent, wherein the stent-graft comprises a graft axially over at least one inner stent and the graft remains sandwiched between the at least one inner stent and the outer frame stent.
It is a further object of the present invention to provide a multi-component endoluminal graft assembly for repairing blood vessels affected by one or more lesions, the multi-component graft comprising a self-expanding endoluminal outer frame stent made of resilient wire, and at least one hollow tubular stent-graft comprising an inner balloon-expandable stent, and a graft made of a fabric material and coaxially arranged within or outside the inner stent, wherein the self-expanding outer frame stent is to be endoluminaly affixed to the blood vessel and the stent-graft is to be arranged coaxially within said self-expanding outer frame stent and affixed to said self-expanding outer frame stent once the self-expanding outer frame stent is expanded and affixed against the vessel, whereby, if the graft is outside the inner stent the fabric graft remains sandwiched between the self-expanding outer frame stent and the inner balloon-expandable stent.
It is still a further object of the invention to provide a use of the above multi-component endoluminal graft assembly comprising a self-expanding endoluminal outer frame stent made of resilient wire, and at least one hollow tubular stent-graft comprising an inner balloon-expandable stent and a graft either within or outside the inner stent, wherein the multi-component graft is endoluminaly implanted in a blood vessel affected by at least one lesion, wherein the outer frame stent is affixed to the vessel and the stent-graft is coaxially within the outer frame stent and affixed to the outer frame stent, whereby, if the graft is outside the inner stent, the graft remains sandwiched between the inner stent and the outer frame stent.
It is even an additional object of the invention to provide a method of implanting a multi-component endoluminal graft assembly in a blood vessel for repairing at least one lesion, the method comprising the steps of:
providing an outer frame stent, either a self-expanding or a balloon expandable stent,
inserting the outer frame stent within the blood vessel at a location for endoluminaly covering at least the lesion and expanding the outer frame stent so as to be deployed at said location and affixed against the blood vessel,
providing at least one hollow tubular stent-graft;
inserting the stent-graft coaxially within the expanded and implanted outer frame stent and expanding the at least one stent-graft so as to be deployed and affixed against at least one portion of the outer frame stent.
It is a further object of the invention to provide a method of implanting a multi-component endoluminal graft assembly in a blood vessel for repairing at least one lesion, the method comprising the steps of:
providing an outer frame stent, either a self-expanding or a balloon expandable stent,
inserting the outer frame stent within the blood vessel at a location for endoluminaly covering at least the lesion and expanding the cuter frame stent so as to be deployed at said location and affixed against the blood vessel,
providing at least one hollow tubular stent-graft comprising:
at least one inner stent, and
a graft coaxially arranged over the at least one inner stent, and
inserting the stent-graft coaxially within the expanded and implanted outer frame stent and expanding the at least one stent-graft so as to be deployed and affixed against at least one portion of the outer frame stent, whereby the graft remains sandwiched between the outer frame stent and the at least one inner stent.